It is common practice to utilize a vise for securing a workpiece when performing work on the workpiece. Such vises are typically utilized on precision machining equipment, such as numeric-control equipment, to clampingly hold a workpiece during a defined machining operation. Such vises typically employ a pair of moving jaw members to hold a workpiece at a working station to perform machining operations thereon. The known vises typically mount the jaw members to keyparts of master jaw elements. The jaw members typically have a connecting passage open on at least one side to enable the respective top to be positioned onto the keypart of the master jaw element by sliding in a direction transverse to the direction of movement of the master jaw element when opening or closing the vise.
One drawback from having an open end or ends on the jaw member is that, during application of a load onto the jaw member, the jaw member can bulge or become uneven due to slight deformation of the metal jaw member at the open end or ends thereof. Further, closing the ends of the metal jaw member prevents turnings or other scrap metal from entering the connecting passageway of the top jaw member.
Accordingly, it is an object of this invention to provide an improved jaw assembly for enabling secure clamping of a workpiece, such as for permitting machining or other manipulations to be carried out with respect to the workpiece, which jaw assembly provides improvements with respect to performance of a vise by closing the ends of the top jaw member being mounted to the master jaw element.
Another preferred object of the invention is to provide an improved jaw assembly which incorporates into the cross section of the top jaw member two dovetail sections. The top jaw member has the same amount of corresponding inclined contact surface for a given depth of the connecting passage while having a substantially smaller width than a corresponding single dovetail jaw member. Of course, the master jaw element must have a keypart projecting upwardly that is designed to fit the jaw member.
Another preferred object of the invention is to provide an improved jaw assembly which includes a master jaw element having a keypart. The improved keypart has a dovetail-shaped portion on one side and a takeup member on the other side thereof. The takeup member has a keeper element extending outwardly therefrom. The keypart mates with a top jaw member having a passage with outwardly inclined dovetail-shaped sections and substantially vertical walls forming a mouth connected to the dovetail-shaped sections. In use, the keeper element extends onto an inclined surface of a wall approaching the dovetail-shaped sections and within about 0.100 inch, preferably 0.060 inch from the vertical wall of the mouth.
It is a further object of the invention to limit the movement of the top jaw relative to the master jaw to the close tolerance clearance distance of about 0.020 inch between an outside facing surface on the master jaw and the immediately adjacent opposing jaw surface.